Chemical and Biological Characterization of a Crude Venom Extract from the Sea Anemone-Bunodosoma Aavernata

Background: Sea-anemones; in common with other members of the phylum cnidaria (coelenterate) possess numerous tentacles containing specialized stinging cells of cnido-cysts. Our main objective is to elucidate the chemical character and biological properties of this Nigerian species of sea anemone Bunodosoma cavernata with a view to providing investigators a scientific basis for future research. Methods: The Nigerian species of sea anemone-Bunodosoma cavernata were collected at Opuaduakiri fishing port in Bonny town; Rivers State; Nigeria. The animal extract was prepared according to standard procedure. The protein content of the extract and percentage protein in the whole animal were also estimated following standard methods. Other biochemical constituents of the animal estimated were the total lipids; carbohydrate; moisture and the mineral content. The stability of the extract and an arbitrary unit of biological activity of the extract were also determined. Results: From the results; the protein content of the crude extract was 0.5 mg protein/ml for a 10-fold diluted extract; while the percentage total protein was about 39.4. The percentage lipid was about 14.9while carbohydrate was probably absent. The moisture content was about 95.7with about 3.4mineral content. The extracts prepared from fresh animals showed the highest activity or potency while the freeze-dried extract lost their potency after about 6 months storage. The result showed that the bulk of the animal was water with very low mineral content. On the biochemical constituents; protein level was the highest and the animal was probably devoid of carbohydrates. Conclusion: We conclude that the anemone (B. cavernata) extract is probably highly toxic and it is very likely that the difficulty in storage which resulted in loss of its biological activities was due to the proteinaeceous nature of the animal

Changes in blood pressure in the rat induced by the venom extract from a sea anemone-Bunodosoma cavernata.

The effect of graded doses of crude sea anemone extract from Bunodosoma cavernata on rat blood pressure was investigated with a view to accessing its effects on the status of the cardiovascular system. From the results, the extract (2-8 ug protein/kg, i.v.) caused only transient hypotension. With higher doses of the extract (10-20 ug protein/kg, i.v.), the transient hypotension was accompanied by a dose-dependent increase in blood pressure. Atropine, mepyramine and propranolol failed to affect the transient hypotension. Of these drugs, only propranolol decreased the extract-induced hypertension. Doses of the extract above 20 ug protein/kg, i.v. produced a decrease in pulse rate and an increase in pulse pressure. We suggest that the extract-induced transient hypotension could be due to the presence of a less potent agent in the extract with acetylcholine-like action, and the hypertensive action of the extract was probably due to the stimulation of the sympathetic division of the autonomic nervous system by agent(s) in the extract.

Blood pressure depression by the fruit juice of Carica papaya (L.) in renal and DOCA-induced hypertension in the rat.

A crude ethanol extract was prepared from the unripened fruit of Carica papaya. Lethality studies showed a dose-mortality relationship with an LD(50) of 325.2 mg/kg in mice administered i.p. Male albino Wistar rats were randomly divided into three batches (15 rats per batch)-renal, DOCA-salt hypertensives and normotensives. Each batch was further divided into three groups-the untreated, hydrallazine and extract treated groups. The mean arterial blood pressure (MAP) and the heart rate were measured in all groups. From the results, the basal (control) MAP were 93.8 +/- 4.5, 175.2 +/- 5. 1 and 181.3 +/- 6.2 mmHg in the normotensive, renal and DOCA-salt hypertensives, respectively. Both hydrallazine (200 microg/100 g i. v) and extract (20 mg/kg.i.v) produced a significant depression of MAP in all groups (p < 0.01 vs controls), but the extract produced about 28% more depression of MAP than hydrallazine in the hypertensive groups. In another group of rats, the extract failed to depress the MAP in rats pretreated with propranolol, but atropine and noradrenaline pretreatment did not prevent the action of the extract on blood pressure. In vitro studies using isolated rabbit arterial (aorta, renal and vertebral) strips showed that the extract (10 microg/mL) produced relaxation of vascular muscle tone which was, however, attenuated by phentolamine (0.5-1.5 microg/mL). It is concluded that the fruit juice of C. papaya probably contains antihypertensive agent(s) which exhibits mainly alpha-adrenoceptor activity.

Biological properties of a venom extract from the sea anemone, Bunodosoma cavernata.

Crude extract was prepared from the sea anemone, Bunodosoma cavernata. The protein content of the extract was estimated to be 0.52 mg protein/ml. The extract was standardized based on the percentage inhibition of histamine-induced contraction of the guinea pig ileum, to determine the biological unit of activity (AU) of the extract. As extracts prepared on different occasions lost potency on storage, the stability of the extract was also investigated. Extracts prepared from fresh animals were about 15% more potent than those prepared from freeze-dried animals. However, freeze-dried animal extracts maintained their potency for about 6 months under storage at -20 degrees C. Lethality studies gave an LD50 of 40 microg protein/kg mice i.p. Also, the crude extract dose-dependently hemolyzed human erythrocytes at room temperature. This activity was favoured by higher temperatures, which peaked at about 60degrees C, and by pH in the alkaline range. We conclude that the crude extract from B. cavernata, though highly toxic, may also contain some biologically active agents which include a haemolytic factor and antihistamine(s), as indicated by its histamine-blocking action.

The coronary vasoconstrictor action of extract IV from the dahlia sea anemone Tealia felina L.

Extract IV, a partially purified preparation of the toxin from the sea anemone Tealia felina, produced marked bradycardia and arrhythmias in the rat in vivo. In the Langendorff rat heart preparation perfused at constant pressure extract IV (0.0224 AU/ml) reduced the force of contraction by 81.3 +/- 7.2%, n = 6, and the coronary flow by 82.0 +/- 4.7%, n = 5. When the preparation was perfused at constant flow rate, extract IV (0.072 AU/ml) increased the coronary circulation resistance from 3.76 +/- 1.09 (control) to 36.94 +/- 12.26 mmHg/ml/min. The force of contraction was also markedly reduced. The extract produced bradycardia in preparations perfused at constant pressure but not in those perfused at constant flow rate. The extract did not affect isolated atria preparations. It was concluded that the bradycardia produced in vivo and in preparations perfused in vitro at constant pressure was probably secondary to the coronary vasospasm produced, which could contribute to the cardiotoxicity of the extract.

The isolation of a toxin from the dahlia sea anemone, Tealia felina L.

Gel chromatography with Dyematrex blue B gel and ion exchange chromatography with a methylcellulose cation exchange column have been used to isolate a toxin present in partially purified saline extracts of the dahlia sea anemone Tealia felina. Toxin activity was assessed by its histaminolytic activity. A ten-fold increase in activity per mg protein was achieved in these two steps. Final purification on a Sephacryl column yielded an apparently pure protein with a molecular weight of 7800. The amino acid composition of this compound was determined.